# How to Calculate Voltage Drop in Series Circuit

To calculate the voltage drop in series circuit, you need to follow these steps:

1. Determine the total resistance of the circuit by adding up the individual resistance values of each component.
2. Measure the current flowing through the circuit using an ammeter.
3. Multiply the current by the total resistance to find the total voltage of the circuit.
4. Measure the voltage at each component in the circuit using a voltmeter.
5. Subtract the voltage of each component from the total voltage to find the voltage drop across each component.

For example, let’s say you have a series circuit with three resistors: R1= 100 ohms, R2= 200 ohms, and R3= 300 ohms. The total resistance of the circuit would be Rtotal= R1 + R2 + R3 = 100 + 200 + 300 = 600 ohms.

If you measure the current flowing through the circuit and find it to be I = 0.5 amps, then the total voltage of the circuit would be Vtotal = I x Rtotal = 0.5 x 600 = 300 volts.

Next, measure the voltage at each resistor using a voltmeter. Let’s say you measure the voltage at R1 to be V1= 50 volts, at R2 to be V2= 100 volts, and at R3 to be V3= 150 volts.

To find the voltage drop across each resistor, subtract the voltage of each resistor from the total voltage:

• The voltage drop across R1 would be Vdrop1 = Vtotal – V1 = 300 – 50 = 250 volts
• The voltage drop across R2 would be Vdrop2 = Vtotal – V2 = 300 – 100 = 200 volts
• The voltage drop across R3 would be Vdrop3 = Vtotal – V3 = 300 – 150 = 150 volts

Therefore, the voltage drop across each resistor in the circuit is 250 volts, 200 volts, and 150 volts, respectively.

Read Also: Use of Voltage Divider

## Application of Ohm’s Law

Ohm’s Law describes the relationship between voltage (V), current (I), and resistance (R) in a circuit, stating that V = IR. It is used to design and analyze circuits and to select components like resistors.

Ohm’s Law

To calculate voltage drop in a series circuit using Ohm’s Law, you need to know the resistance of the circuit (R) and the current flowing through the circuit (I).

In a series circuit, the total resistance (RT) is equal to the sum of the individual resistances in the circuit. So, if you have n resistors in series, the total resistance can be calculated using the formula:

RT = R1 + R2 + R3 + … + Rn

Once you know the total resistance, you can use Ohm’s Law (V = IR) to calculate the voltage drop (VD) across each resistor. The voltage drop across a specific resistor is proportional to its resistance, so the voltage drop across each resistor can be calculated using the formula:

VD = IRn

where n is the number of the resistor you are interested in.

For example, let’s say you have a series circuit with three resistors: R1 = 10 ohms, R2 = 20 ohms, and R3 = 30 ohms. The total resistance of the circuit would be:

RT = R1 + R2 + R3 = 10 + 20 + 30 = 60 ohms

If the current flowing through the circuit is 2 amps, you can calculate the voltage drop across each resistor using Ohm’s Law:

VD1 = IR1 = 2 x 10 = 20 volts VD2 = IR2 = 2 x 20 = 40 volts VD3 = IR3 = 2 x 30 = 60 volts

So the voltage drop across R1 is 20 volts, across R2 is 40 volts, and across R3 is 60 volts.